So on the minibus returning from the show I drew most of this on my trusty and very much loved Hudl (first gen):

Depressed Slug. Hudl, Adobe Photoshop Touch, eBay stylus.

Then, on my walk about leaves yesterday I used my HUdl 2 to take a couple of texture photos which I thought would suit the picture. When I got home I emailed them to myself (not having any better idea to transfer the files, Android is still a mystery to me in some ways) and added them to the picture which gave me this:

…which is miles better (although not for the slug obviously).

Then, overnight (while I was semi-successfully sleeping) I realised I should have moved the mouth and added a small outline to the slug. Which gave me this:

And so on. I might change the outlines in the foot imprint but for the most part will stick with it where it is. Mmmm sluggy.